4E assessment and 3D parametric analysis of an innovative liquefied natural gas production process assisted by a diffusion-absorption refrigeration unit

Cumulative electricity demand in the world's energy portfolio has elicited in focusing new energy carriers. Herein, a single mixed refrigerant (SMR) LNG process, precooled with a diffusion-absorption refrigeration (DAR) system, is proposed and appraised through 4E assessment and 3D parametric analyses. The SMR subsystem feeds on 63,850 kg/h of natural gas at 6650 kPa, and, utilizing 331,630 kW of waste heat, the DAR subsystem transfers 139,306 kW of refrigeration duty, at - 29.62 degrees C to the SMR, and thereby 57,850 kg/h LNG is produced. The results indicate the cost per unit exergy of 13.54 $/GJ and cost rate of 90.71 $/s regarding the LNG output. Also, the exergy destruction cost rate percentage share in most components is higher than the investment cost rates. The T-100 tower had the largest exergy destruction cost rate at 64,763.52 $/h, while the COMP-102 compressor had the highest investment cost rate at 1821.35 $/h. The nominal interest rate increases the exergoeconomic factor and the overall cost rate in the case of the T-100 tower. The annualized cost of system (ACS) analysis indicated the ACS at 100.458 M$/year with a levelized cost of product (LCOP) at 0.198 $/kg LNG. The exergoenvironmental evaluation signposted that the total environmental impact is the highest in air coolers AC-100 and AC-101, respectively. Finally, the 3D parametric showed that compressor C-100 isentropic efficiency and inlet temperature of the tower T-100 had non-consistent connotation, whereas compressor C-100 pressure ratio and heat exchanger HX-102 minimum approach temperature had consistent connotation. [GRAPHICS] .

Automated summary

A single mixed refrigerant (SMR) LNG process, precooled with a diffusion-absorption refrigeration (DAR) system, is proposed and evaluated in this study. The results show that the cost per unit exergy is 13.54 $/GJ and the cost rate is 90.71 $/s for the LNG output. The analysis also reveals that the investment cost rates differ significantly from the exergy destruction cost rates in most components.